Rutherford Appleton Laboratory RAL Masterclasses 2009 INTRODUCTION A Very Brief Guide to Accelerators Glenn Patrick Rutherford Appleton Laboratory http://hepwww.rl.ac.uk/pust/masterclass.htm

Microscopes & Telescopes ~ 400 Years Ago Galileo’s telescope, ~1609, Florence Magnification ~30 Compound microscope ~1670, Glasgow Magnification ~30 Micrographia Robert Hooke, 1665 Siderius Nuncius, Galileo Galilei, 1610

Small Scales and Large Scales - Today Large Hadron Collider (2009) Hubble Ultra Deep Field (2004)

Particle Physics Astronomy E = mc2 E  kT

Higher energies means shorter wavelengths. Probing Matter Higher energies means shorter wavelengths.

Cosmic Particles Accelerators! Interactions in the atmosphere Low flux of particles Difficult to identify/control Accelerators!

Charged Particle Beams Force on charged particle is given by the Lorentz Force e+ e- Electric Field Acceleration Magnetic Field Bending Cathode(-) Anode(+) p+ e-

John Cockroft & Ernest Walton Voltage Multiplier 1897 – J.J. Thomson John Cockroft & Ernest Walton Voltage Multiplier Cavendish Laboratory, 1932.

Cockroft/Walton Pre-Injectors 750kV FermiLab 665 kV ISIS, RAL (replaced 2004)

+ + + - + Fermilab (400 MeV) LINEAR ACCELERATORS - Alternating RF voltage. Each step gives a small energy increase to the particle.

2 mile Linear Accelerator, SLAC, Stanford World’s straightest building World’s longest building

Circular Accelerators Cyclotron First circular particle accelerator built by Ernest O. Lawrence & Stanley Livingston at Berkeley in 1930. Energy = 80 keV, Diameter = 13cm 13 cm

Principal Components of a Synchrotron In a Collider, bunches of particles/antiparticles circulate in opposite directions.

Super Proton Synchrotron CERN, Geneva (6km circumference)

Radio Frequency Cavities LEP (CERN) Large Electron Positron Collider (LEP) 1989-2000 27 km circumference 3,000 bending magnets 800 focussing magnets 11,000 revolutions/sec

Electromagnetic waves accelerate particles in the same way that waves propel surfers. Timing is vital!

Correction of chromatic spread. Focussing Magnets Quadrupole (LEP) Strong Focussing Beam alternately focussed in horiz and vert planes. Sextupole (LEP) Correction of chromatic spread.

HERA – Electron Proton Collider (6.3 km) Hamburg, 1992-2007 920 GeV protons 27.5 GeV electrons/positrons p e ɣ proton

Collides protons and anti-protons Tevatron, FermiLab, Chicago Tevatron Main injector Collides protons and anti-protons Energy = 1 TeV (1000 GeV) 4 mile circumference

Synchrotron Radiation Diamond Light Source  e You are here Started operation Feb 2007. Uses synchrotron radiation for studies at molecular/atomic level.

International Linear Collider The Next Generation? ~31 km 250 GeV electrons colliding with 250 GeV positrons 8 February 2007 Reference Design Report 2010 – 2012 Technical Design Phase ? Construction/Operation

Masterclass Programme 09:30 Arrival, Coffee and Doughnuts (R18) 10:00 Welcome Caroline Callard 10:05 A Very Brief Guide to Accelerators Dr. Glenn Patrick 10:20 Fundamentals of Particle Physics Dr. Stefania Ricciardi 11:00 Introducing Diamond Dr. David Price 11:15 Introducing ISIS Dr. Martyn Bull 11:35 Group A: Visit to ISIS or Diamond Group B: Computer Session Drs. Tricoli & Wielers 12:30 Buffet Lunch (R18) 13:30 The Large Hadron Collider Dr. Kristian Harder 14:15 Group B: Visit to ISIS or Diamond Group A: Computer Session Drs. Tricoli & Wielers 15:15 Tea 15:30 Applications of Particle Accelerators Dr. Rob Edgecock 16:00 Question and Answer Session 16:15+ End Material can be found at: http://hepwww.rl.ac.uk/pust/masterclass.htm

Energy Units! Electron Volt – Energy gained by an electron when accelerated in an electric field through a potential difference of 1 volt. 1 eV = 1 electron Volt Energy to ionise hydrogen = 13.6 eV 1 keV(kilo) = 1,000 eV = 103 eV Medical X-ray ~ 200 keV 1 MeV(Mega) = 1,000,000 eV = 106 eV Alpha particle decay of uranium 4.2 MeV 1 GeV(Giga) = 1,000,000,000 eV = 109 eV LEP collider beam (1989-200) = 45 GeV 1 TeV(Tera) = 1,000,000,000,000 eV = 1012 eV Highest energy accelerator in world = 1 TeV (Tevatron) Highest energies found in cosmic rays (>1020 eV)